Chronic stress in pregnant rats: effects on growth rate, anxiety and memory capabilities of the offspring

Female rats were repeatedly stressed for 10 periods of 15 min by the presen ce of a cat, at the 10th (S10) or the 19th (S19) gestational day. The litte r from stressed females often contained a majority of males or a majority o f females, especially in the S19 group. The death of pups was dramatically high in the S19 group and, compared with controls, growth of the surviving animals was slower. When adult, their long-term memory was altered and they exhibited an aversive behavior relative to wide areas. Moreover, cognitive alterations were revealed by the low level of exploration and the inabilit y to rapidly process the relevant environmental cues. These deficits resemb le those of psychiatric patients who had been submitted to pre-natal stress . (C) 2000 Elsevier Science B.V. All rights reserved.